Burglar-alarm.



W. N. FAWGETT. BURGLAR ALARM. APPLICATION FILED JULY 31. 1908.

Patented May 4, 1909.

b 7k 4?. flaw Inventor: .y B E (l g Attyr UNITED STATES WILLIAM N.FAWOETT, OF NEW YORK, N. Y., ASSIGNOH 0F ()Xli-llfddi 'iU I\l;\l'l(lf8BRUCKUEDIER, OF NEW YORK, X. Y.

BURGLAR-ALARM.

Application filed July 31, 1908.

K burglar alarms and particularly to that class of burglar alarms knownas closed circuit burglar alarms.

The object of this invention is to provide a new and improved attachmentwhich instantly breaks the circuit whenever wires drawn across skylightopenings, or ceilings or walls, are out, after having been shortcircuited or are stretched or strained or )ulled aside to permit passageof a person, which at tachment is simple in construction, can easily beapplied, and is very effective and reliable in action.

In the accompanying drawings, in which like characters of referenceindicate like parts in all the figures :Figure 1 is a plan view of myimproved automatic switch. Fig. 2 is a side view of the same. Fig. 3 isa diagram showing parts of a single wire circuit combined with myswitch.

The switch is mounted on a base 1 of insulating material of suitablesize. The switch lever 2 is provided with a longitudinal slot 3 throughwhich a headed stud. 4 passes into a boss 5 on the base 1 so that theswitch lever can swing on this pivot and can slide in the direction ofits length. One end 6 of the switch lever extends into a longitudinalgroove 7 formed in the side of an upright 1 plate 8 on the base 1 saidplate 8 being slightly shorter than the are that can be described bysaid contact end of the switch lever in its swinging movements. A bailshaped check piece 9 extends over the contact end of the switch lever 2which can i strike against the upright ends of the check piece 9. Aspring 10 has one end secured at 11 on the base and its opposite end isattached to that end of the switch lever opposite the contact end 6. Awire 12 forming part of the closed burglar alarm circuit is alsoattached to that end of the switch lever to which the spring 10 isattached. 13 also forming part of the burglar alarm circuit is connectedwith the plate 8. The wire 12 is secured to an insulated binding post atSpecification of Letters Patent.

A wire l atented May 4, 1909.

Serial No. 146.318.

1% and then passed to and fro across an opening 15, such as a s y lightopening or over a wall or ceiling and at its change of di-- rection ispassed li'iescly over or around insulated pulley" or rods 16 and the endof wire 12 is attached to the s stated.

The wire 12 is so proportioned in length. that when his drawn taut itholds the switch lever 2 hi central osition on the plate 1* and thespring 10 is brought ito greater ten..ion. The wire 1? is so spaced inits com'olutions over the opening 15 that a man cannot enter unless thiswire is cut or forced to one side. The burglar encountering this wirewould not cut it unless he had '1 t short circuited it by uniting thepoints, iv wire. If he then cuts the i the points a and Z) the to"spring ll) is at once released and this spring in contracting throws theswitch lever against the end oi the stop bridge. or check piece wherebythe contact betw' the switch lever '2 and the plate 8 l the end of theswitch lever passes end of the plate mahii j a clean break. This breakin the usual manner operates the signal, thus ing notice that the wirehas been cut or tampered with. The switch lever while swing is alsomoved lengthwise as far as the slot 3 allows, and is moved to such anext nt across the end of the plate 8 as to be in .nc-d as sho i Fig. 1and cannot be 1 f" pulling on the wire z b the It on the other hand thewire not cut by the burglar but is Forced to one side the additionalstrain on this wire expands the spring 10 to a greater ex and i thecontact end 6 or the switch lever l Fig. 1, until it arrives at theother end of the plate 8 Fig. 1, and snaps over the same thus break'ngthe circuit and at the same time locking the switch lever. This breakthus made also gives a si lz'ii showing that some one has tampered withthe wires oi the burglar alarm system.

I have illustrated and described my device as applied on a closedcircuit local battery system. it can of course be used equally as wellon any closed circuit system, for example, such as derive the circuitfrom an outside source, as in all cases my switch breaks the circuitmechanically whenever the taut holding wire is cut or strained suliiitchlever 2 as ...i ,1 Sunni.

ciently to form an opening or passageway oi greater Width than thatformed between the convolutions of the wire as originally adjusted foruse.

What I claim as new and desire to secure by Letters Patent is 1. in aburglar alarm, the combination with a base, of a switch member pivotedon the base to swing in the arc of a circle, a contact piece againstwhich one end of the switch lever rests and a spring connected with theopposite end of the switch lever, and the conductor wire connected withthe switch lever to hold the same in position and in opposition to thespring, substantially as set forth,

In a burglar alarm, the combination with a base, of a switch leverhaving a lo; {'itudinal slot, a pivot passing tnrough said slot into thebase so as to permit the switch lever to swing and to move in thedirection toward the lived member with which one end of the movablemember is normally in contact and a spring connected with said, movablemember to hold said end against l the fixed membe, and l toe conductorwire connected with the switch lever to hold the same in position and inopposition to the spring, substantially as set forth.

3. In a burglar alarm, the combinationi with a base, of a switch leverhaving a longit tudinal slot, a pivot passing through said i slot intothe base so as to permit the switch lever to swing and to move in thedirection l toward the fixed member, with which one end of the movablemember is normally in contact and a spring connected with said movablemember to hold said end in contact, said fixed switch member having agroove in its side into which groove the tree end oi the movable memberextends and the corn ductor wire connected with the switch lever to holdthe s no in pOSitlOll and in onposition to the spring, substantially asset iorth. in a burglar alarm, the combination with a base plate, of amovable switch mem ber provided with longitudinal slot, a pivot passingthrough the slot into the base member, whereby said movable switchmember can swing on its pivot and move in the direction 01'' its length,a fixed member with which one end. of the switch member is in contact,said fixed switch member having less length than the are described bythe end of the movable member and the conductor wire connected with theswitch lever to hold the same in position and in opposition to thespring, substantially as set forth.

5. ln burglar alarm, the combination with a base plate, of a movableswitch member provided with a longitudinal slot, a pivot passing throughthe slot into the base member, whereby said movable switch member canswing on its pivot and move in the direction of its length, a fixedmember with which one end or" the switch member is in contact, saidcontact member being on the chord of an arc of the circle described bythe contact end oi" the movable member, and being ol less length thansuch chord and the conductor wire connected with the switch lever to holthe same in posit'on and in )position ie spring, substantially as setiorth.

in a burglar alarm, the combination with a base plate, of a switch levermounted rereon to swing in the arc of circle and to nove in thedirection oi its length, a contact iiece against which one end of theswitch er rests, a spring con: ected with the switch lever to press itsend toward the direction of the contact piece, and a stop for the switchlever and located beyond each end of the contact piece and the conductorwire connected with the switch lever to hold the same in position andopposition to the spring, substantially as set forth.

7. in a burglar alarm, the combination with an electrical circuit, of aswitch, both members of which form part of said circuit, a spring actingon the movable member of the switch, a restraining means in the shape ofan electrical conductor, for preventing the spring from moving themovable member of the switch. said restraining means also form ing partor the circuit and guides around which said restraining means isPZLSSQfl loosely, substantially as forth.

in testimony whereof, I have signed. my name to this specification inthe presence 01 two subscribing witnesses, this 27th day of July, 1908.

WliililAiii N. llillVOiCVl.

()sclin F. GUNZ, K. G. Luann.

